<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body, ul{
      margin: 0;
      padding: 0;
    }

    body{
      background-image: url(../images/grid.png);
    }
    svg{
      background-color: rgba(255, 0, 0, 0.1);
    }
  </style>

</head>
<body>

  <svg width="100" height="100" xmlns="http://www.w3.org/2000/svg" >
    <path d="M 80 0,L 20 50, L 80 100 Z"></path>
  </svg>

  <svg width="100" height="100" xmlns="http://www.w3.org/2000/svg" >
    <polygon points="20 0, 80 50, 20 100"></polygon>
  </svg>

</body>
</html>